Tillage effects on soil properties, crop responses and root density of sweet pepper (Capsicum annuum)

Abstract

Aim of study: Soil compaction causes an increase in bulk density, resistance to penetration, low diffusion of oxygen and water in the soil. Tillage is one of the techniques to alleviate compaction. The objective of this work was to evaluate the effects of tillage on sweet pepper grown in greenhouse soil.Area of study: The experimental work was conducted in a plastic greenhouse at the Experimental Station of the University of Almería (SE Spain).Material and methods: The soil was ploughed with a single pass with ripper to 15 cm depth and with rotavator to 10 cm depth. The control treatment was soil untilled. Crop dry matter production and root length growth and density of sweet pepper were evaluated, in addition to soil characteristics such as bulk density, resistance to penetration and soil matric potential.Main results: Tillage reduced soil bulk density from 1.70 to 1.60 kg L-1 in the 10-40 cm of soil depth. There was a notable reduction in irrigation (12%), total N applied (13%), drainage (91%) and N leaching (95%) in the tillage treatment. However, tillage did not improve significantly crop dry matter production and yield. The absence of tillage effect is possible due to a slight reduction in the bulk density of the soil.Research highlights: The tillage treatment produced a notable reduction in irrigation, total N applied, drainage and N leaching when compared to the control.

Enhancing Root Distribution, Nitrogen, and Water Use Efficiency in Greenhouse Tomato Crops Using Nanobubbles

“…This root distribution in the control management has already been described by Padilla et al [39] in greenhouse pepper cultivation in the province of Almería and may be due to situations of continued hypoxia as a result of the combined effect of the decrease in air-filled porosity due to the high relative saturation of the soil maintained constantly throughout the crop (Supplementary Materials Figure S1) [60,61] and low dissolved oxygen in irrigation water [62] Hypoxia conditions, which weaken the aerobic respiration of roots, modify root distribution [6,23,63,64] and can result in decreased energy metabolism and reduced crop yield. The presence of nanobubbles with low buoyancy, high persistence in the irrigation solution, and strong gas mass transfer ability allows air or oxygen to be continuously dissolved in the soil pore water which will favour root respiration in the moisture-saturated zones around the emitter and at depth, increasing the efficiency of water and nutrient uptake [22,63,65]. This effect seems to translate into higher values of the ANUE (agronomic nitrogen use efficiency) and fWUE (field water use efficiency) indices obtained for the nanobubble treatments (Table 7).…”